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Articles 186211 - 186240 of 250127

Full-Text Articles in Life Sciences

Contents, Discovery Editors Jan 2002

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

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Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J. F. Alvarez Barreto, D. Julie Carrier, E. C. Clausen Jan 2002

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J. F. Alvarez Barreto, D. Julie Carrier, E. C. Clausen

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

High-value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs occur. When compared to traditional solvents, water is an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A, and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50°C, 70°C, 85°C and 100°C water as a function of time. For taxifolin, silychristin, silybinin A, and silybinin B, …

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Expression Patterns Of Novel Wound-Inducible Plant Genes In Medicago Truncatula, Mandy M. Cox, Kenneth L. Korth Jan 2002

Expression Patterns Of Novel Wound-Inducible Plant Genes In Medicago Truncatula, Mandy M. Cox, Kenneth L. Korth

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Terpenoids are an important class of defensive compounds that can accumulate in plants after pathogen infection or injury by chewing insects. Clones encoding putative terpene synthases and an oxidosqualene synthase, isolated from insect-damaged Medicagotruncatula leaves, were selected from an expressed sequence tag (EST) database. The cDNA clones were used as radiolabeled probes to analyze gene expression in leaves treated by known factors that can trigger a defense response in plants. Transcript levels for all of the genes examined increased in response to artificial wounding, insect herbivory, and methyl jasmonate (meJA) treatments, whereas salicylic acid (SA) and glucose oxidase (GOX) had …

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Organophosphate Toxicosis In Chickens: A Case Report, Robert Hubbard, Judith England, E. Dustan Clark Jan 2002

Organophosphate Toxicosis In Chickens: A Case Report, Robert Hubbard, Judith England, E. Dustan Clark

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Two cases of organophosphate toxicity were diagnosed at the University of Arkansas Poultry Science Department poultry research farm in the Spring of 2002. In both cases the birds were being treated with the organophosphate RaVap® for Northern Fowl Mites (Ornithonyssus sylvarium) infestations. A total of 61 birds died and 13 were treated successfully with atropine sulphate.

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The Influence Of Storing High Moisture-Content Rough Rice On Milling Quality, Julita M. Manski, Terry Siebenmorgen Jan 2002

The Influence Of Storing High Moisture-Content Rough Rice On Milling Quality, Julita M. Manski, Terry Siebenmorgen

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The objective of this research was to determine the influence on drying characteristics of storing high-moisture content (MC) rough rice under various conditions and durations before drying. Two cultivars of rice, 'Bengal', a medium-grain cultivar, and 'Cypress', a long-grain cultivar, were used. The MC of 'Bengal' was 24.8%1 and that of 'Cypress' was 20.4% at harvest. Immediately after harvest, drying runs were performed with samples of both cultivars under two drying air conditions: one at 51.7°C (125°F) and 25% relative humidity (RH), and the other at 60°C (140°F) and 17% RH. Storage treatments using the high MC rice were also …

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Bradyrhizobium Japonicum And Soybean Symbiotic Response To Glyphosate In Glyphosate-Tolerant Soybeans, Jodie M. Scheele, C. Andy King, Marilynn K. Davies, Larry C. Purcell Jan 2002

Bradyrhizobium Japonicum And Soybean Symbiotic Response To Glyphosate In Glyphosate-Tolerant Soybeans, Jodie M. Scheele, C. Andy King, Marilynn K. Davies, Larry C. Purcell

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Soybean (Glycine max) grain contains approximately 40% protein and 6.5% nitrogen (N) on an elemental basis. Therefore, the plant requires an abundant N supply throughout its life cycle, and symbiotic N fixation of soybean with Bradyrhizobium japonicum provides 40 to 85% of the soybean N. Although soybean cultivars have been genetically engineered to withstand the herbicide glyphosate, B. japonicum grown in culture is sensitive to glyphosate. We hypothesized that glyphosate applied to glyphosate-tolerant soybean would inhibit nodulation by B. japonicum unless B. japonicum could also be selected for glyphosate tolerance. Cultures of B. japonicum were challenged with sublethal doses of …

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Discrimination Of Cardiac Health And Disease By Assessment Of Heart Rate Variability: Wavelet Vs. Fast Fourier Transformation, Jusonda Leray Derouen Jan 2002

Discrimination Of Cardiac Health And Disease By Assessment Of Heart Rate Variability: Wavelet Vs. Fast Fourier Transformation, Jusonda Leray Derouen

LSU Master's Theses

The autonomic nervous system (ANS) modulation of the heart is of clinical importance because of its relevance to risk of life threatening arrhythmic events. Decomposition of heart rate variability (HRV) has been used to quantify ANS control of the heart. The traditional method for frequency analysis has involved the use of fast Fourier transformation (FFT). However, heart rate data typically violate assumptions of the FFT. Therefore, the assessment of HRV may benefit from other, potentially more suitable, mathematical approaches. For example, the discrete wavelet transformation (DWT) appears to have promise with respect to its ability to discriminate between healthy and …

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One-Week Stability Of Forearm Venous Outflow As Assessed By Venous Occlusion Plethysmography, Jennifer Pitre Ortego Jan 2002

One-Week Stability Of Forearm Venous Outflow As Assessed By Venous Occlusion Plethysmography, Jennifer Pitre Ortego

LSU Master's Theses

The aim of this study was to test short-term and long-term reliability of venous outflow (VO) indices using the venous occlusion plethysmography technique. A secondary purpose was to compare venous measures to age, gender and various anthropometrical measures. The study group consisted of apparently healthy males and females, aged 18 to 80 years. Venous indices were under measures on two occasions (1 week apart), under the conditions of rest and following 5 min of upper arm occlusion. Venous outflow measures were calculated from the area under the curve (AUC) as well as the plethysmographic curve technique at the time .5 …

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Litter And Ground Dwelling Spiders Of Mixed Mesophytic Forest In Southeast Louisiana, Joyce Fassbender Jan 2002

Litter And Ground Dwelling Spiders Of Mixed Mesophytic Forest In Southeast Louisiana, Joyce Fassbender

LSU Master's Theses

During Pleistocene glaciation much of the southeastern United States was covered with mixed mesophytic hardwood forest. These forests are composed predominantly of magnolia, holly, and beech with a mixture of other tree species, such as oak and hickory, and a distinct understory. Remnants of mixed mesophytic hardwood forests occur in the southern United States and are important refugia for disjunct and habitat-restricted species. In Louisiana, the mixed mesophytic forest habitat is found mostly in West Feliciana Parish, particularly in the area around St. Francisville. I chose two sites to conduct a study of spider diversity in litter habitats of disturbed …

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The Effect Of Nocturnal Sampling On Semen Quality And The Efficiency Of Collection In Bovine Species, Jennifer H. Yates Jan 2002

The Effect Of Nocturnal Sampling On Semen Quality And The Efficiency Of Collection In Bovine Species, Jennifer H. Yates

LSU Master's Theses

The objective of this study was to evaluate two semen collection schedules utilizing the assumed behavioral differences between bovine species. The efficiency was measured by bull behavior and semen quality parameters. Four Holstein and four Brahman bulls were collected each during a morning and a night collection time weekly. Ejaculates (n=64) were obtained via artificial vagina over four-weeks. To avoid masking benefits of night collection, the first collection of the week was alternated between night and day. Two collection teams were employed to reduce the time needed for collection, and the variability in collection method. Sampling order and collection team …

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Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 3 2002, Several Authors Jan 2002

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 3 2002, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

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The Treatment Efficiency Of Plankton In The İvedik Drinking Water Treatment Plant, Ankara, Ni̇lsun Demi̇r, Doğan Atay Jan 2002

The Treatment Efficiency Of Plankton In The İvedik Drinking Water Treatment Plant, Ankara, Ni̇lsun Demi̇r, Doğan Atay

Turkish Journal of Biology

The phyto-zooplankton composition and some physical and chemical properties of drinking water were investigated in the İvedik water treatment plant. The mean values of phytoplankton abundance were 641±92 and 438±55 ind/ml in the Kurtboğazı and Çamlıdere inlets, respectively. More than 50% of the phytoplankton belonging to the classes Bacillariophyceae, Chlorophyceae, Cryptophyceae and Dinophyceae were removed in the clarifiers. The treatment efficiency of phytoplankton ranged from 89 to 100% after the last chlorination. The mean values of zooplankton abundance were 93±23 and 59±18 ind/l in the Kurtboğazı and Çamlıdere inlets, respectively. The treatment efficiency of zooplankton varied between 97% and 100% …

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Tanapseudes Gutui, A New Species Of Apseudomorphan Tanaidacea (Crustacea: Peracarida) From The Caribbean Sea And The Taxonomic Status Of The Family Tanapseudidae Băcescu, Thomas Hansknecht, Richard W. Heard, Roger Bamber Jan 2002

Tanapseudes Gutui, A New Species Of Apseudomorphan Tanaidacea (Crustacea: Peracarida) From The Caribbean Sea And The Taxonomic Status Of The Family Tanapseudidae Băcescu, Thomas Hansknecht, Richard W. Heard, Roger Bamber

Gulf and Caribbean Research

Tanapseudes gutui, n. sp., is described from depths of 3–34 m off San Juan, Puerto Rico, and 4– 5 m off Goat Island, Tobago. Tanapseudes sinensis Bamber from Hong Kong waters is re-examined and determined to represent a junior synonym of the type species T. ormuzana Băcescu which was originally collected in the Straights of Hormuz off Iran. Tanapseudes gutui can be distinguished from T. ormuzana by several characters including details of the mouth parts, the presence of a reduced spiniform seta on the distotergal margin of the propodus of pereopod 1, pereonites 3–6 with rounded anterior margins, and …

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Measuring Emission Rates Of Particulate Matter From Fan Ventilated Swine Barns (2002), B Z. Predicala, Ronaldo G. Maghirang Jan 2002

Measuring Emission Rates Of Particulate Matter From Fan Ventilated Swine Barns (2002), B Z. Predicala, Ronaldo G. Maghirang

Kansas Agricultural Experiment Station Research Reports

Methods for measuring concentrations and emission rates of particulate matter (PM) from mechanically ventilated livestock buildings were evaluated in a laboratory facility and in a swine-finishing barn. Concentrations of PM were measured inside the room (room sampling) and at the exhaust duct (exhaust sampling). Concentrations at the exhaust duct were determined using high-volume traverse downstream of the exhaust fan, low-volume traverse downstream of the fan, and fixed sampling upstream and downstream of the fan. The traverse methods, which served as the reference, were conducted under isokinetic conditions; fixed sampling was done under both isokinetic and sub-isokinetic conditions. Compared to the …

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Effects Of Mannanoligosaccharide And Sodium Chlorate On Growth Performance Of Nursery Pigs During An Acute Enteric Disease Challenge With Salmonella Enterica Serotype Typhimurium (2002), T E. Burkey, Jerome C. Nietfeld, B J. Johnson, J Ernest Minton, Steven S. Dritz Jan 2002

Effects Of Mannanoligosaccharide And Sodium Chlorate On Growth Performance Of Nursery Pigs During An Acute Enteric Disease Challenge With Salmonella Enterica Serotype Typhimurium (2002), T E. Burkey, Jerome C. Nietfeld, B J. Johnson, J Ernest Minton, Steven S. Dritz

Kansas Agricultural Experiment Station Research Reports

A 28-day experiment was conducted to compare the effects of feeding mannanoligosaccharides (mannan) and sodium chlorate (chlorate) to weanling pigs as a possible substitute for the commonly used antimicrobialcarbadox. Pigs were fed experimental diets for 2 wk, then challenged orally with Salmonella enterica serotype typhimurium to establish enteric disease. Average daily gain and ADFI were greater for pigs fed carbadox than all other treatments in the 2 wk following infection. During the first week after infection, pigs fed chlorate had greater G/F than control pigs, and pigs fed mannan tended to have greater G/F than control pigs. There were no …

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Active Formation Of Mixed-Species Grouse Leks: A Role For Predation In Lek Evolution?, Robert M. Gibson, Andrea S. Aspbury, Leonard L. Mcdaniel Jan 2002

Active Formation Of Mixed-Species Grouse Leks: A Role For Predation In Lek Evolution?, Robert M. Gibson, Andrea S. Aspbury, Leonard L. Mcdaniel

School of Biological Sciences: Faculty Publications

Behavioral ecologists have interpreted avian leks as products of sexual selection, in which males display socially to increase their opportunities to mate. However, without invoking reproductive queuing or kin selection, this paradigm does not necessarily explain why many males that fail to mate participate in leks. An alternative solution, that males also aggregate to reduce predation, has previously lacked compelling support. We show that mixed-species leks, comprising two congeneric grouse, form when single males or small groups of one species, the greater prairie chicken Tympanuchus cupido, join leks of another, the sharp-tailed grouse T. phasianellus. We documented the …

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Clone Size Of Andropogon Gerardii Vitman (Big Bluestem) At Konza Prairie, Kansas, Kathleen H. Keeler, Charles F. Williams, Linda S. Vescio Jan 2002

Clone Size Of Andropogon Gerardii Vitman (Big Bluestem) At Konza Prairie, Kansas, Kathleen H. Keeler, Charles F. Williams, Linda S. Vescio

School of Biological Sciences: Faculty Publications

Clone size of plants of Andropogon gerardii from Konza Prairie Biological Station, Manhattan, Kansas was estimated from spatial patterns of genetic variation, using proteins detected by starch gel electrophoresis and DNA content (ploidy) measured by flow cytometry. Unique multi-locus protein banding patterns and differences in ploidy were used to exclude plants as members of the same clone. Individual clones averaged about 2 m in diameter and areas of prairie of 100 m2 were calculated to contain an average of 31.8 genetic individuals.

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Identification And Distribution Of Masked And Hayden's Shrews (Genus Sorex) In Iowa, Howard P. Whidden, Alison W. Ray, John B. Bowles Jan 2002

Identification And Distribution Of Masked And Hayden's Shrews (Genus Sorex) In Iowa, Howard P. Whidden, Alison W. Ray, John B. Bowles

Journal of the Iowa Academy of Science: JIAS

Masked shrews (Sorex cinereus) and Hayden's shrews (S. haydeni) are both reported from Iowa, but the two species are difficult to tell apart and their relative distributions in Iowa have been unclear. We took 13 skull measurements and examined 2 qualitative features on more than 300 specimens of Sorex from Iowa. The vast majority of our specimens could be identified easily by cranial measurements, and more than half could be identified by the relative position of the maxillary plate. We found no evidence for intergradation between the two species. Masked shrews are present throughout most of Iowa, whereas Hayden's shrews …

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Back Cover Jan 2002

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Soybean Canopy Gap Influence On Velvetleaf Seed Production, Shawn R. Wright, Micheal D. K. Owen, Douglas D. Buhler Jan 2002

Soybean Canopy Gap Influence On Velvetleaf Seed Production, Shawn R. Wright, Micheal D. K. Owen, Douglas D. Buhler

Journal of the Iowa Academy of Science: JIAS

Gaps in the soybean row provide locations for velvetleaf (Abutilon theophrasti) plant growth. Gap width, and velvetleaf plant location within the gap, were investigated for effect on seed production. There was no significant difference in velvetleaf capsule production between plants that grew either centered in a gap or at the western end of a gap in east-west oriented soybean rows. Also, there was no difference in plant survival, emergence through the soybean canopy, flowering, locule number per capsule, or average seed weight of velvetleaf based on gap width. However, there was a difference in capsule production based on gap width. …

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Master Conservationist Awards, John Owens Jan 2002

Master Conservationist Awards, John Owens

John Owens: Speeches and Appearances

It is a distinct pleasure to be with you this evening to present the Master Conservationist awards. I appreciate the opportunity to recognize those who have gone the extra mile to enhance Nebraska's natural resources and our way of life. Their efforts take on even more importance in a year like this when drought conditions have threatened field crops, pastures, and rangeland, as well as water for livestock and the citizens of our state. Times like this underscore how important it is for us to recognize the delicate balance of nature.

The Master Conservationists we honor tonight have long-recognized the …

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Book Review - North American Box Turtles: A Natural History, Neil P. Bernstein Jan 2002

Book Review - North American Box Turtles: A Natural History, Neil P. Bernstein

Journal of the Iowa Academy of Science: JIAS

While I have only studied box turtles for four years, from the beginning, I was quickly impressed at the many studies and observations that had been published on North American box turtles. At the same time, I was also frustrated by the lack of syntheses of the material. For the beginning researcher or interested layperson, organizing the studies into a cohesive whole was daunting, and I attempted my own loose compilation that took me most of a summer. However, there is now a new book that provides the background and overview that I sought. C. Kenneth Dodd, a longtime researcher …

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Book Review - The Guide To Iowa's State Preserves, Cornelia F. Mutel Jan 2002

Book Review - The Guide To Iowa's State Preserves, Cornelia F. Mutel

Journal of the Iowa Academy of Science: JIAS

The Iowa State Preserves System gives the highest protection afforded by law to sites "dedicated for maintenance as nearly as possible in [their] natural condition." To date, ninety sites have been dedicated as biological, geological, archaeological, scenic, or historic preserves, declaring that such use is the site's "highest, best, and most important use for the public benefit" (State Preserves Act of 1965). In a state as dramatically altered as Iowa, such remnants are of intense interest to professional and amateur naturalists of all inclinations, as well as to anyone who appreciates nature. Yet understanding the basic qualities of these preserve …

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Editorial Board & Iowa Academy Of Science Officers And Directors Jan 2002

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Cover - Table Of Contents Jan 2002

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Effects Of Cattle Grazing On Woodlands In Central Iowa, Cathy Mabry Jan 2002

Effects Of Cattle Grazing On Woodlands In Central Iowa, Cathy Mabry

Journal of the Iowa Academy of Science: JIAS

Iowa's forests have undergone a dramatic decline in area since settlement by Europeans. Most of the remaining forests have been degraded by an assortment of human impacts, with cattle grazing the most prominent among them. Using a matched pairs study designed to control for environmental differences among plots, I examined the impact of cattle grazing on the forest understory, canopy trees, and tree regeneration. There were distinct groups of understory species associated with ungrazed and grazed plots. Species associated with ungrazed plots were all native and tended to be perennial herbs with fleshy roots. Ungrazed plots also had species preferring …

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Science Safety Status In Iowa Schools, Gerlovich A. Jack, Rahul Parsa, Bruce Frana, Theresa Stiner Jan 2002

Science Safety Status In Iowa Schools, Gerlovich A. Jack, Rahul Parsa, Bruce Frana, Theresa Stiner

Journal of the Iowa Academy of Science: JIAS

Between May and December 2001, 574 Iowa science teachers participated in a statewide science safety project supported by financial assistance from the Iowa Department of Natural Resources. Part one of the project focused on assessing the status of safety in Iowa secondary science programs. Part two was to provide teachers with information, tools, and training to address the identified needs. Three safety concerns were identified: one was associated with the age of lab facilities and two were related to safety training of teachers.

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Awards And Recognition, Iowa Academy Of Science, 2002 Jan 2002

Awards And Recognition, Iowa Academy Of Science, 2002

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Editorial Board & Iowa Academy Of Science Officers And Directors Jan 2002

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Familial Amyotrophic Lateral Sclerosis-Associated Mutations Decrease The Thermal Stability Of Distinctly Metallated Species Of Human Copper/Zinc Superoxide Dismutase, Jorge A. Rodriguez, Joan S. Valentine, Daryl K. Eggers, James A. Roe, Ashutosh Tiwari, Robert H. Brown Jr., Lawrence J. Hayward Jan 2002

Familial Amyotrophic Lateral Sclerosis-Associated Mutations Decrease The Thermal Stability Of Distinctly Metallated Species Of Human Copper/Zinc Superoxide Dismutase, Jorge A. Rodriguez, Joan S. Valentine, Daryl K. Eggers, James A. Roe, Ashutosh Tiwari, Robert H. Brown Jr., Lawrence J. Hayward

Chemistry and Biochemistry Faculty Works

We report the thermal stability of wild type (WT) and 14 different variants of human copper/zinc superoxide dismutase (SOD1) associated with familial amyotrophic lateral sclerosis (FALS). Multiple endothermic unfolding transitions were observed by differential scanning calorimetry for partially metallated SOD1 enzymes isolated from a baculovirus system. We correlated the metal ion contents of SOD1 variants with the occurrence of distinct melting transitions. Altered thermal stability upon reduction of copper with dithionite identified transitions resulting from the unfolding of copper-containing SOD1 species. We demonstrated that copper or zinc binding to a subset of “WT-like” FALS mutants (A4V, L38V, G41S, G72S, D76Y, …

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